That's absolutely right,the shop have give you the right advise,you shall get regular tires,at least 'till you gete all those leaks fixed.
Also consider having the engine flushed with sea foam,the most synthetic oil use by 99.9 % of us the mobil 1 also royal purple & amsoil.
Also change all differential fluids as well as the T-case & transmmission;As you said you have no clue when last the previous owner did it.
Repacking or replacing all four bearing is a good thing to do along with new brake pads & rotors.flushing the brake fluid,radiator & probably a full tune up is needed to improve performance & MPG.
You got a lot of work to do GRIF,hope you can really enjoy it as much as you want.
Keep us posted on the progress & don't forget there's a lot of info in here usefull to you.